Dynamic interaction between valve-closure water hammer wave and centrifugal pump

2021 ◽  
pp. 095440622110007
Author(s):  
Wenqi Zhang ◽  
Shuai Yang ◽  
Dazhuan Wu ◽  
Zhongtian Xu
Keyword(s):  
Axial Direction ◽  
Dynamic Interaction ◽  
Water Hammer ◽  
Equipment Failure ◽  
Valve Closure ◽  
Force Amplitude ◽  
Optimal Position ◽  
Force Variation ◽  
Pressure Surge ◽  
Interaction Position

Water hammer is a principal cause of pipeline and equipment failure in pumping systems. The numerical method and experiments are used to investigate the dynamic interaction between the valve-closure water hammer wave and pump, to study the pressure variation and fluid-induced force on the pump components. The impeller-volute interaction and impeller position are taken into consideration. Results show that the valve-closure water hammer wave generates a substantial fluid-induced force on the pump and leads to a pressure surge in the pipeline. Meanwhile, the impeller-volute interaction also causes pressure and force variation in the pipeline and pump. The force amplitude caused by this factor in the axial direction is similar to that caused by the water hammer wave but is much smaller in the radial direction. The different interaction position of the water hammer wave on the blades can weaken the force, by 13.11% and 13.18% for the impeller and volute when the blades are under the most optimal position, respectively.

On the Optimum Utilization of Water Hammer

1988 ◽  
Vol 202 (4) ◽  
pp. 249-256 ◽  
Author(s):  
P H Azoury ◽  
M Baasiri ◽  
H Najm
Keyword(s):  
Water Hammer ◽  
Valve Closure ◽  
Pipe Length ◽  
A Value ◽  
Closure Time ◽  
Highly Sensitive ◽  
Pressure Surge ◽  
Comparison Of The Results ◽  
Optimum Water ◽  
Valve Area

The computerized method of characteristics was used to analyse, for a single pipeline discharging into the atmosphere, the effects of valve-closure schedule and pipe length on optimum water-hammer strength. It was found that the criteria of optimum water-hammer utilization are a non-linear inherent valve schedule in which the bulk of the pressure surge occurs near the beginning or towards the end of valve closure, together with as small a value of dimensionless valve-closure time and as high a value of wide-open valve area as is consistent with cavitation-free operation. Also, a comparison of the results with hydraulic ram test data suggests that optimum drive pipe length may be based solely on optimum water-hammer strength, in the light of the relative effects of pipe friction and dimensionless valve-closure time. In general, optimum pipe length is not highly sensitive to inherent valve-closure schedule, water-hammer strength, pipe size or reservoir head.

Maximum Pressure Head Due to Linear Valve Closure

1991 ◽  
Vol 113 (4) ◽  
pp. 643-647 ◽  
Author(s):  
Chyr Pyng Liou
Keyword(s):  
Flow Characteristic ◽  
Pressure Head ◽  
Head Loss ◽  
Water Hammer ◽  
Point Of View ◽  
Global Perspective ◽  
Maximum Pressure ◽  
Valve Closure ◽  
Subtle Effect ◽  
Dimensionless Variables

The maximum pressure head resulting from one-speed closure of wide open valves is investigated. The dimensionless variables formulated in this study make the subtle effect of the initial valve head loss explicit and separate from that of the pipe frictional head loss. The maximum head is related to initial pipe frictional head loss, the initial valve head loss, the inherent flow characteristic of the valve, and the closure period by plots of dimensionless variables. The trends of the variation of the maximum pressure head are discussed. An example is used to illustrate the usage of the plots, and to show the advantage of having a global perspective of the phenomenon in the selection and sizing of valves from the water hammer point of view.

Water Hammer Likely Cause of Large Oil Spill in North Sea

2009 ◽  
Author(s):  
Erik D. Nennie ◽  
Harry J. C. Korst ◽  
Knud Lunde ◽  
Rune Myklebust
Keyword(s):  
North Sea ◽  
Oil Spill ◽  
High Pressures ◽  
Water Hammer ◽  
Loading Capacity ◽  
Operating Pressure ◽  
Multiple Reflections ◽  
Loading System ◽  
History Of ◽  
Pressure Surge

On December 12, 2007, the second largest oil spill in the history of Norwegian oil exploration occurred on StatoilHydro’s Statfjord Alpha platform. The spill was caused by a snapped 20″ oil off-loading hose. Thorough investigations by StatoilHydro [1] and by the Norwegian authorities [2] revealed the chain of events that led to this incident. One of the links in this chain was the unintended fast closure of the shuttle tanker’s bow loading valve during off-loading. This closure initiated a pressure surge in the oil off-loading system. As part of the internal investigation by StatoilHydro, TNO carried out a water hammer analysis of the entire oil off-loading system, including the off-loading hoses to the seabed and further subsea piping up to the platform. These simulations revealed that high pressures could occur in the oil off-loading system due to fast closure of the bow loading valve followed by multiple reflections at diameter changes. The maximum pressures were more than 100 bar above the normal operating pressure of 10 bar. The diameter changes were introduced into the oil off-loading system to maximize the off-loading capacity. The results of the water hammer analysis provided the missing link between the fast closure of the valve and the damaged hose and also showed that this damage most likely occurred within 0.5 second after the closure of the valve. Based on the results of this analysis, also other oil off-loading systems are being reinvestigated to prevent a similar incident to occur in the future.

The Sensitivity of Counterweighted Swing Check Valve Performance to Counterweight Location

2003 ◽  
Author(s):  
L. I. Ezekoye
Keyword(s):  
Flow Resistance ◽  
Reverse Flow ◽  
Check Valve ◽  
Fast Response ◽  
Water Hammer ◽  
Flow Reversal ◽  
Reverse Direction ◽  
Valve Closure ◽  
Forward Flow ◽  
Opening And Closing

Check valves are used to minimize flow reversal. In general, the two primary design objectives of installing a check valve in a system include quick opening in forward flow and fast closure in reverse flow. The fast response requirements in both opening and closing directions are challenging. In the opening direction, the concern is to minimize forward flow resistance and, in the reverse direction, the objective is to minimize flow reversal and avoid water hammer. Check valve manufacturers have often used counterweights to permit quick opening or quick closing. The drawback of forward flow counterweight check valves is that in the flow reverse direction, the counterweights may retard valve closure. The location of the counterweight could further complicate the performance of the check valve. Misaligning the counterweight can also affect check valve performance. The use of quick closing counterweights present similar challenges. This paper examines the interaction of counterweight location and alignment on the performance of check valves.

scholarly journals Experimental Study of the Effectiveness of a Combined Closure of the End Gate Pipeline Valve

2019 ◽  
Vol 66 (1-2) ◽  
pp. 3-13
Author(s):  
Henrikh H. Herasymov ◽  
Ievgenii G. Gerasimov ◽  
Sergiy Y. Ivanov ◽  
Oleg L. Pinchuk
Keyword(s):  
Experimental Data ◽  
Gate Valve ◽  
Break Point ◽  
Water Hammer ◽  
Valve Closure ◽  
Hydraulic Shock ◽  
Reliable Operation ◽  
Irrigation Systems ◽  
Pipeline Valve ◽  
Pressure Pipeline

Abstract One of the ways to ensure a reliable operation of irrigation systems is to protect them from water hammer (hydraulic shock) damage that occurs when starting or stopping a pumping station. This can be achieved by creating conditions in which a water hammer will not occur in the pressure pipeline as a result of closing the end gate valve (EGV). The aim of the present study was to investigate processes occurring in the pipeline during a linear closure of the EGV, during a closure with one break point and during an intermittent closure, as well as to verify the effectiveness of a combined end gate valve closure of the pipeline. Based on experimental data and calculations, the article recommends a linear closure of the EGV with one break point.

Exploring the performances of the dual technique-based water hammer redesign strategy in water supply systems

2019 ◽  
Vol 69 (1) ◽  
pp. 6-17 ◽  
Author(s):  
Mounir Trabelsi ◽  
Ali Triki
Keyword(s):  
Pressure Wave ◽  
Oscillation Period ◽  
Conventional Technique ◽  
Water Hammer ◽  
Water Supply Systems ◽  
Piping System ◽  
Wave Oscillation ◽  
Pressure Surge ◽  
Short Section ◽  
Steel Piping

Abstract This paper explored and compared the effectiveness of the inline and branching redesign strategies-based dual technique, implemented to enhance the conventional technique skills in terms of attenuation of positive and negative pressure surge magnitudes and limitation of the spreading of pressure wave oscillation period. Basically, this technique is based on splitting the single inline or branched plastic short-section, used in the conventional technique, into a couple of two sub-short-sections made of two distinct plastic material types. Investigations addressed positive and negative surge initiated water hammer events. Additionally, high and low density polyethylene materials were utilized for sub-short-section material. Results illustrated the reliability of the dual technique in protecting hydraulic systems from excessive pressure rise and drop, and evidenced that the (HDPE/LDPE) sub-short-sections' combination (where the former sub-short-section is attached to the sensitive region of the steel piping system parts, while the latter is attached to the second extremity of the steel piping system) is the most prominent configuration providing the best trade-off between pressure surge attenuation, and pressure wave oscillation period spreading. Lastly, it was found that the pressure head peak (or crest) and the pressure wave oscillation period values were markedly sensitive to the (HDPE) sub-short-section length and diameter.

Analysis of Passive Water Hammer

1999 ◽  
Author(s):  
Syed M. Husaini ◽  
Asif H. Arastu ◽  
Riyad Qashu
Keyword(s):  
Flow Velocity ◽  
Water Column ◽  
Power Plants ◽  
Cold Water ◽  
Water Hammer ◽  
Saturated Water ◽  
Pipe Segment ◽  
Pressure Surge ◽  
Active Flow

Abstract This paper presents a methodology for the calculation of the severity a type of water hammer called “passive water hammer”. The passage of a cold water column followed by hot saturated water through a restricting orifice causes a reduction in flow velocity and a corresponding increase in pressure. The term passive water hammer was given to this mechanism because there is no active flow intervention required for its initiation. This type of water hammer has been observed in heater drain systems of power plants. An example is given for the calculation of pressure surge and pipe segment forces due to this mechanism.

Understanding Line Packing in Frictional Water Hammer

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Jim C. P. Liou
Keyword(s):  
Numerical Methods ◽  
Wave Front ◽  
Water Hammer ◽  
Maximum Pressure ◽  
Valve Closure ◽  
Governing Equations ◽  
Front Line ◽  
Wave Fronts ◽  
Friction Term

For valve closure transients in pipelines, friction attenuates the amplitude of water hammer wave fronts and causes line packing. The latter is a sustained head increase behind the wave front. Line packing can lead to overpressure. Because of the nonlinearity of the friction term in the governing equations of water hammer, a satisfactory analytical explanation of line packing is not available. Although numerical methods can be used to compute line packing, an analytical explanation is desirable to better understand the phenomenon. This paper explains line packing analytically and presents a formula to compute the line packing that leads to the maximum pressure at the closed valve.

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